Injector training device

ABSTRACT

A training device for training a user on the operation of an auto-injector that dispenses a medicament. A needle guard is slidable from a first extended position relative to a housing prior to operation of the training device, to a retracted position during operation of the training device, and to a second extended position after operation of the training device. An actuation assembly controls the movement of the needle guard from the retracted position to the second extended position. A lock locks the needle guard in the second extended position. A safety is proximate a proximal end of the housing and prevents movement of the needle guard from the first extended position to the retracted position in a storage position. The needle guard is moveable into the retracted position with the safety in an armed position. The safety resets the lock upon returning the safety to the storage position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/017,418, filed Jun. 25, 2018, which is a continuation of U.S. patentapplication Ser. No. 14/774,106, filed on Sep. 9, 2015, now U.S. Pat.No. 10,013,895, which is a U.S. National Stage Entry of InternationalPatent Application PCT/US2014/023883, filed on Mar. 12, 2014, which inturn claims the benefit of U.S. Provisional Patent Application No.61/778,937 filed Mar. 13, 2013 entitled “Injector Training Device”,which are incorporated by reference herein in their entirety.

BACKGROUND OF THE INVENTION

The present invention generally relates to an injector training deviceand, more particularly, to a training device for an auto-injector.

Automatic injectors are devices for enabling an individual toself-administer a dosage of a liquid medicament subcutaneously orintramuscularly.

A typical auto-injector has a housing, inside of which is a cartridgecontaining medicament. During use, a needle extends from theauto-injector into the user such that the medicament is subsequentlyforced through the needle and into the user. After delivery of the doseof medicament into the injection site, a needle shield may safely coverand shield the used needle tip from further use. In otherauto-injectors, the device is needleless and the medicament is deliveredthrough the skin by a jet injection.

It is often important that the user of an auto-injector learn its properoperation and become comfortable with its use. Users should, nothesitate to inject themselves, either from fear of using the device orfor lack of knowledge in the proper use of the device, especially duringa critical moment when an injection is required. However, it isimpractical for individuals to train with automatic injectors byrepeatedly injecting themselves. Thus, there is a need for a device thatsimulates the operation of an auto-injector whereby the user canpractice and become familiar with the auto-injector's operation prior todispensing any medicament. Training with such a device may help toprevent improper administering of the medicament, improper orienting ofthe auto-injector, and premature removal of the auto-injector prior tothe full dispensing of the medicament.

SUMMARY OF THE INVENTION

In one embodiment there is a training device for training a user on theoperation of an auto-injector that dispenses a medicament, the trainingdevice comprising: a housing having a distal end and a proximal end; aneedle guard slidably received with the distal end of the housing, theneedle guard slidable from a first extended position relative to thehousing prior to operation of the training device, to a retractedposition relative to the housing during operation of the trainingdevice, and to a second extended position relative to the housing afteroperation of the training device; an actuation assembly coupled to theneedle guard, the actuation assembly having a biasing member and a lock,the actuation assembly controlling the movement of the needle guard fromthe retracted position to the second extended position, the lock lockingthe needle guard in the second extended position in a locked position;and a safety proximate the proximal end of the housing, the safetypreventing movement of the needle guard from the first extended positionto the retracted position in a storage position, the needle guardmoveable into the retracted position with the safety in an armedposition, the safety resetting the lock upon returning the safety to thestorage position.

In one embodiment, the lock is a leaf spring. In one embodiment, theleaf spring includes a first leg and a second leg. In one embodiment,the leaf spring includes only a first leg. In one embodiment, the firstleg includes a radially extending lock tab that restricts movement ofneedle guard relative to housing in the second extended position, andthe second leg includes a radially extending resistance tab thatprovides a resistance force that must be overcome to move the needleguard to the retracted position. In one embodiment, the first legincludes a radially extending lock tab that restricts movement of needleguard relative to housing in the second extended position. In oneembodiment, the first leg includes a projection proximal to the locktab, in one embodiment, the leaf spring is attached to the actuationassembly by a fastening means. In one embodiment, the fastening meansfor attaching the leaf spring is riveted to the actuation assembly is arivet. In one embodiment, the actuation assembly includes a trigger, thetrigger retaining the lock in the storage position, the needle guardsliding the trigger off of the lock when the needle guard is moved fromthe first extended position to the retracted position. In oneembodiment, the safety slides the trigger back over the lock between thelocked position and the storage position. In one embodiment, the safetyis removably coupled to the housing, removing the safety from thehousing allows the user to urge the needle guard into the retractedposition in the armed position, and reattaching the safety to thehousing resets the lock to the storage position.

In one embodiment, the needle guard extends from the distal end of thehousing in the first extended position a distance equal to a distancethe needle guard extends from the distal end of the housing in thesecond extended position, in one embodiment, a predetermined force, inaddition to the force of the biasing member, must be exerted on theneedle guard relative to the housing to move the needle guard out of thefirst extended position. In one embodiment, a first projection of thesafety extends into the proximal end of the housing and a secondprojection of the safety extends into a sidewall of the housing in thestorage position. In one embodiment, the training device does notinclude a needle. In one embodiment, the training device does notcontain medicament. In one embodiment, the training device is notcapable of injecting medicament.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The following detailed description of embodiments of an injectortraining device, will be better understood when read in conjunction withthe appended drawings of an, exemplary embodiment. It should beunderstood, however, that the invention is not limited to the precisearrangements and instrumentalities shown.

In the drawings:

FIG. 1 is a perspective view of a training device in accordance with anexemplary embodiment of the present invention shown in a storageposition;

FIG. 2 is an exploded perspective view of the training device shown inFIG. 1;

FIG. 3 is a perspective view of a leaf spring in accordance with anexemplary embodiment of the present invention;

FIG. 4 is a perspective view of a leaf spring in accordance with anotherexemplary embodiment of the present invention;

FIG. 5A is a roar elevational view of the training device of FIG. 1shown in a storage position;

FIG. 5B is a side cross sectional view of the training device shown inFIG. 5A taken along line A-A;

FIG. 5C is an enlarged partial side cross sectional view of the trainingdevice shown within section B of FIG. 5B;

FIG. 6A is a rear elevational view of the training device of FIG. 1shown in an armed position showing the safety and safety cap, removedfrom the training device;

FIG. 6B is a side cross sectional, view of the training device shown inFIG. 6A taken along line A-A;

FIG. 6C is an enlarged partial sidle cross sectional view of tiertraining device shown within section B of FIG. 6B;

FIG. 7A is a rear elevational view of the training device of FIG. 1shown in an armed position;

FIG. 7B is a side cross sectional view of the training device shown inFIG. 7A taken along line A-A;

FIG. 7C is an enlarged partial side cross sectional view of the trainingdevice shown within section B FIG. 7B;

FIG. 8A is a rear elevational view of the training device of FIG. 1shown in a partially retracted position;

FIG. 8B is a side cross sectional, view of the training device shown inFIG. 8A taken along line A-A;

FIG. 8C is an enlarged partial side cross sectional view of the trainingdevice shown within section B of FIG. 8B;

FIG. 9A is a rear elevational view of the training device of FIG. 1shown in a retracted position;

FIG. 9B is aside cross sectional view of the training device shown inFIG. 9A taken along line A-A;

FIG. 9C is an enlarged partial side cross sectional view of the trainingdevice shown within section B of FIG. 9B;

FIG. 10A is a rear devotional view of the training device of FIG. 1shown in a partially extended position;

FIG. 10B is a side cross sectional view of the training device shown inFIG. 10A taken along line A-A;

FIG. 10C is an enlarged partial side cross sectional view of thetraining device shown within section B of FIG. 10B;

FIG. 11A is a rear view elevational view of the training device of FIG.1 shown in a locked position;

FIG. 11B is a side cross sectional view of the training device shown inFIG. 11A taken along line A-A;

FIG. 11C is an enlarged partial side cross sectional view of thetraining device shown within section B of FIG. 11B;

FIG. 12A is a rear elevational view of the training device of FIG. 1shown in a reset storage position;

FIG. 12B is a side cross sectional view of the training device shown inFIG. 12A taken along line A-A; and

FIG. 12C is an enlarged partial side cross sectional view of thetraining device shown within section B of FIG. 12B.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings in detail, wherein like reference numeralsindicate like elements throughout, there is shown in FIGS. 1-12C atraining device, generally designated 10, in accordance with anexemplary embodiment of the present invention.

Training device 10 is a training tool used to educate users on theproper orientation and operation of a corresponding auto-injector. Theauto-injector of interest may require steps to arm the device, a certainamount of force t activate injection and/or make noises that a user maynot be familiar with particularly before using an auto-injector for thefirst time. Training device 10 simulates the operation of anauto-injector so that a user can practice administering a medicament andget comfortable with how the auto-injector works without actually usingthe needle or dispensing the medicament. Unlike the auto-injector,training device 10 contains no medicament or needle assembly. Trainingdevice 10 may have the same look an feel as a particular auto-injectoror a particular type of auto-injector so a user can become comfortablewith using the auto-injector by practicing with training device 10.Training device 10 may be resettable to allow a user to repeat thesimulated injection operation until the user becomes comfortable withits operation. Additionally, training device 10 may be used to trainmultiple individuals on the proper operation of an auto-injector. Assuch, family members can be educated on the proper operation of theauto-injector to assist the user. Furthermore, training device 10 may beused as a training aid in a hospital, clinic, or physician's office.

Training device 10 may be used to train users on a variety ofauto-injector configurations. In one embodiment, training device 10 isused to train users on use of Antares Pharma's VIBEX™ auto-injector. Inone embodiment, training device 10 is used to train users on anauto-injector that injects methotrexate. In one embodiment, trainingdevice 10 is used to train users on an auto-injector that injectsepinephrine. In one embodiment, training device 10, though resettable,is used to train users on single use auto-injectors. In otherembodiment, training device 10 is used to train users on anauto-injector similar to those disclosed in U.S. Patent ApplicationPublication Nos. 2012/0157965 and 2011/0144594 and U.S. ProvisionalPatent No. 61/607,339 which are hereby incorporated by reference intheir entirety.

Referring to FIGS. 1 and 2, training device 10 includes a housing 12extending along longitudinal axis A and has a distal end 12 a andproximal end 12 b. As used herein, movement along longitudinal axis A orin a direction generally parallel to longitudinal axis A is referred toas moving longitudinally, distally and/or proximally. It is noted that,in the context of this disclosure, the terms “distal” and “proximal” areused in reference to the position of training device 10 relative to auser of the injection device when merely held by a user. Accordingly, apoint located distal to a second point would be further from the user(e.g., towards an injection end of training device 10) and vice versa.Also as used herein, movement is a direction perpendicular tolongitudinal axis A is referred to as moving radially. Housing 12couples, contains and/or protects the remaining components of trainingdevice 10. Housing 12 may be shaped and configured to be grasped by asingle hand of a user. In one embodiment, housing 12 has a flattenedrear side 12 e and a rounded front side 12 f. In such an embodiment,during use a user may grasp training device 10 with their pinkyproximate distal end 12 a and their thumb proximate proximal end 12 bsuch the user's finger tips engage the flattened side 12 e and theuser's palm wraps around rounded side 12 f. The user may, however, grasphousing 12 in any radial orientation relative to their hand that feelscomfortable.

Housing 12 may be comprised of a distal portion 12 c and a proximalportion 12 d that are secured to one another during assembly by afastener such as a snap fit. In other embodiments, distal portion 12 c,and proximal portion 12 d of housing 12 are coupled to one another inany manner such a thread, adhesive, or press fit. In other embodiments,distal portion 12 c and proximal portion 12 d of housing 12 areintegrally formed. Housing 12 may be transparent such that the user cansee the interior components. In other embodiments, housing 12 ispartially or entirely opaque to conceal one or more interior components.Housing 12 may include indicia 14, such as for example an arrow with thephrase “needle end” to indicate which end of training device 10 is thesimulated injection end. In other embodiments, indicia 14 may includetrademarks, drug information and/or injection instructions such a listof steps for how to use training device 10.

Training, device 10 may include a safety cap 16 coupled to distal end 12a of housing 12. Certain auto-injectors may include a safety cap similarto safety cap 16 to cover and protect the needle tip before use. Safetycap 16 may be provided so that a user practices with removing a similarsafety cap from an auto-injector. Safety cap 16 may be coupled to distalend 12 a of housing via threads 18 such that safety cap 16 must betwisted relative to housing 12 to remove safety cap 16 from distal end12 a of housing 12. In one embodiment, threads 18 extend partiallyaround the perimeter of distal end 12 a such that only a partialrotation of safety cap 16 relative to housing 12 is required to removesafety cap 16 from housing 12.

Safety cap 16 may be further coupled to distal end 12 a of housing 12via one or more fasteners such as a snap fit. In one embodiment, thefasteners include a projection 20 (see FIG. 6B) extending radiallyinward from safety cap 16 that are configured to snap fit intocorresponding grooves or apertures 22 in housing 12 (see FIG. 2). In oneembodiment, the fasteners include projections 24 extending radiallyinward from safety cap 16 that are configured to engage correspondingprojections 30 a extending radially outwardly from a needle guard 30(see FIG. 6B). One or more fasteners coupling safety cap 16 and housing12 may be configured to prevent safety cap 16 from being removed fromhousing 12 solely by pulling safety cap 16 distally from housing 12. Inone embodiment, coupling and recoupling safety cap 16 with housing 12creates an audible click to indicate that the safety cap 16 has beensecured or removed respectively. In one embodiment, twisting safety cap16 relative to housing 12 allows for safety cap 16 to be decoupled andremoved from housing 12. In one embodiment, pulling safety cap 16distally from housing 12 without twisting safety cap 16 relative tohousing 12 will not result in safety cap 16 decoupling from housing 12.The coupling between safety cap 16 and housing 12 may include otherconfigurations such as the inverse projection/aperture configurationshown in the drawings and/or other devices such as detents, latches ormagnets.

Safety cap 16 may include indicia 26 such as for example an arrow withthe word “twist” to indicate how to remove safety cap 16 from housing12. In other embodiments, indicia 26 may include trademarks and/orinjection instructions.

Safety cap 16 may include one or more grips 28 to help a user grasp andtwist safety cap 16 relative to housing 12. Grips 28 may include one ormore projections or textured areas that increase the friction between auser's fingers and safety cap 16. In one embodiment, safety cap 16includes two grips 28 diametrically opposed from one, another.

Housing 12 may include one or more viewing windows 8 configured to allowa user to see inside the housing 12. A corresponding auto-injector mayhave similar windows to allow a user to see the level of medicament. Oneor more components such as needle guard 30 may include correspondingapertures 6 that align with windows 8. Windows 8 may be comprised of atransparent material. In one embodiment, a larger portion of the housing12 is comprised of a transparent material and a sticker or decal coversthe housing 12 leaving windows 8 exposed. Two windows 8 may be providedthat are generally diametrically opposed from one another so that a usercan see at least partially through the training device 10. In oneembodiment, windows 8 are provided on the side surfaces. In otherembodiments, windows 8 are provided on the top and bottom.

Referring to FIG. 2, in one embodiment, training device 10 includes aneedle guard 30 slidably received with distal end 12 a of the housing12. Certain auto-injectors may include a needle guard similar to needleguard 30 to cover and protect a needle before and/or after use. In anauto-injector, the needle guard may extend over the needle before use,expose the needle in a retracted position during use and re-cover theneedle after use. Such needle guards may require a predetermined amountof force to expose needle and then lock out over the needle followinguse to prevent or at least reduce accidental needle sticks. Trainingdevice 10 may include a needle guard 30 similar to a needle guard ofcertain auto-Injectors so that a user is familiar with its operation.

As will be described in further detail below, in some embodiments,needle guard 30 is slidable from a first extended or storage positionrelative to housing 12 prior to operation of training device 10 (seeFIGS. 5A-7C), to a retracted position relative to housing 12 duringoperation of training device 10 (see FIGS. 8A-9C), to a second extendedor locked position relative to housing 12 after operation of trainingdevice 10 (see FIGS. 10A-12C) and resettable to the storage position(see FIGS. 12A-12C).

Referring to FIG. 2, training device 10 may include an actuationassembly coupled to needle guard 30 configured to control movement ofneedle guard 30 relative to housing 12. The actuation assembly mayinclude a biasing member 32 and a lock 34. In one embodiment, biasingmember 32 is disposed between needle guard 30 and lock 34 to urge needleguard 30 longitudinally away from lock 34. Lock 34 may be coupled to alatch 40. Latch 40 may be coupled to housing 12. In one embodiment,latch 40 does not move relative to housing 12. A sleeve 38 may beprovided, between biasing member 32 and latch 40. In other embodiments,biasing member 32 is coupled directly to latch 40. In one embodiment,biasing member 32 is a helical compression spring. In other embodiments,biasing member 32 is an elastomer, one or more springs of anyconfiguration or a gas powered device.

Referring to FIG. 2, lock 34 may be controlled by a trigger 42. In oneembodiment, trigger 42 is controlled by a safety 44 and the needle guard30. In one embodiment, trigger 42 is slidably coupled to a proximal endof latch 40 to hold lock 34 at least partially within latch 40 in thestorage mode and allow lock 34 to at least partially extend radiallyoutwardly through latch 40 in the locked position. Trigger 42 mayinclude a flattened portion 42 a. In one embodiment, trigger 42 includesdiametrically opposed flattened portions 42 a. In one embodiment,flattened portion 42 a is configured to slidably engage a projection 34c of lock 34. In one embodiment, trigger 42 is keyed to latch 40 toprevent trigger 42 from rotating, relative to latch 40 and keepflattened portion 42 a aligned with projection 34 c of lock 34. In oneembodiment, trigger 42 includes a notch 42 c proximate the distal end offlattened portion 42 a. In one embodiment, notch 42 c is shaped andconfigured to receive a projection 34 c of lock 34, in one embodiment,trigger 42 includes a projection 42 b that extends into a slot 40 c inlatch 40. In one embodiment, trigger 42 includes two diametricallyopposed projections 42 b that extends into diametrically opposed slots40 c in latch 40. In one embodiment, trigger 42 is generally symmetricalabout a plane parallel with longitudinal axis A.

In one embodiment, safety 44 includes at least one projection 44 a thatextends into housing 12 to prevent trigger 42 from sliding proximallyrelative to latch 40 and lock 34. In one embodiment, at least oneprojection 44 a is coupled to housing via a snap fit. Safety 44 mayinclude a projection 44 c that engages with needle guard 32. In oneembodiment, projection 44 c extends into, housing 12 and prevents needleguard 30 from moving proximally toward proximal end 12 b. In oneembodiment, projection 44 e extends from an arm 44 b. In one embodiment,arm 44 b extends into slot 12 g in housing 12 such that arm 44 b isgenerally flush with the outer contour of housing 12. In one embodiment,safety 44 includes a tab 44 d that extends distally from safety 44. Inone embodiment, tab 44 d is generally parallel with arm 44 b. In oneembodiment, tab 44 d is diametrically opposed to arm 44 b. In oneembodiment, tab 44 d includes one or more grips 44 e (see FIG. 6A) tohelp a user push safety 44 from housing 12. Grips 44 e may include oneor more projections, or textured areas that increase the frictionbetween a user's fingers (such as a thumb) and tab 44 d.

Referring to FIGS. 2 and 3, lock 34, in one embodiment, is a leafspring. Lock 34 may be coupled to latch 40. In one embodiment, lock 34is fastened to latch 40. In one embodiment, lock 34 is fastened to latch40 by a rivet 46. Lock 34 may include one or more apertures 34 d. In oneembodiment, rivet 46 extends through aperture 34 d. Lock 34 may includeat least one additional aperture 34 d. In one embodiment, a projection40 b extending from latch 40 may extend through one or more additionalapertures 34 d (see FIG. 5C). In one embodiment, lock 34 includes threeapertures 34 d. In one embodiment, one or more apertures 34 d on eitherside of rivet 46 receive a projection from latch 40 to prevent lock 34from twisting relative to latch 40. In other embodiments, lock 34 isfastened to, latch 40 by one or more of a screw, adhesive, spot weldand/or is coupled to latch 40 by the configuration of latch 40 (e.g.,latch 40 may include a slot that lock 34 is slid through).

Referring to FIG. 3, lock 34 may include one or more cantilevers armsforming one or more leaf springs. In one embodiment, lock 34 has agenerally flat proximal end and one or more distally extending armsforming one or more leaf springs. Lock 34 may include a lock arm 34 a.In one embodiment, leek arm 34 a is coupled to latch 40 such that lockarm 34 a extends toward distal end 12 a. Lock arm 34 a may include alock tab 34 b. In one embodiment, lock tab 34 b extends radially fromlock arm 34 a. Lock tab 34 b may include a support 34 g. Support 34 gmay be provided to lock tab 34 b to add rigidity and reduce or preventlock tab 34 b from bending such as when lock tab 34 b is abutted byneedle guard 30 as discussed below. In one embodiment, support 34 g isformed by an indent in lock tab 34 b. In one embodiment, support 34 gextends distally from lock tab 34 b. In other embodiments, support 34 gmay be formed by additional material or thickness added to lock tab 34b.

Lock arm 34 a may include a projection 34 c proximal to lock tab 34 b.Projection 34 c may be sloped at least on a side facing the proximaldirection. In one embodiment, projection 34 c is generally V-shaped. Inon embodiment, projection 34 c is tapered as it extends radially fromlock arm 34 a. In one embodiment, projection 34 c is formed by bends(e.g., three) in lock are 34 a. In other embodiments, projection 34 cmay be additional material or an attachment extending from lock arm 34a. Lock 34 may include a resistance arm 34 e. In one embodiment,resistance arm 34 e is generally parallel with lock arm 34 a. Resistancearm 34 e may include a resistance tab 34 f. In one embodiment,resistance tab 34 f extends radially from resistance arm 34 c. In someembodiments, the angle between resistance tab 34 f and resistance arm 34e may be set depending on the desired resistance for retracting needleguard 30. In one embodiment, resistance tab 34 f extends in the oppositedirection than lock tab 34 b. In other embodiments, such as lock 34′shown in FIG. 4, resistance arm 34 e is omitted entirely.

Referring to FIG. 2, in one embodiment, projection 34 c extends throughand from latch 40. In one embodiment, lock tab 34 b extends radiallythrough and from latch 40. In one embodiment, lock tab 34 b extendsradially through an aperture 40 a in latch 40 such that a portion oflatch 40 extends over lock arm 34 a in between lock tab 34 b andprojection 34 c. In one embodiment, resistance tab 34 f extends radiallythrough and from latch 40.

Referring to FIGS. 5A-5C, training device 10 is shown in a storageposition. The storage position, in some embodiments, is the initialposition or the position that the user begins with training device 10.As shown in FIGS. 5A and 5B, safety cap 16 may be coupled to distal end12 a of housing 12 in the storage position. Safety cap 16 may bedetached from and reattached to housing 12 without impacting the storageposition of the other components (e.g., without causing movement ofneedle guard 30 relative to housing 12). In other embodiments, removingsafety cap 16 may cause training device 10 to enter an armed position.In the storage position, in one embodiment, projection 44 c of safety 44extends into housing 12 and radially past a portion of needle guard 30such that needle guard 30 abuts projection 44 c and is prevented frommoving proximally relative to housing 12. In the storage position, inone embodiment, trigger 42 is coupled to the proximal end of latch 40such that it extends over projection 34 c. In one embodiment, withprojection 34 c pushed radially into latch 40, lock arm 34 a is biasedfurther into latch 40 such that lock tab 34 b is within latch 40 and outof the traveling path of needle guard 30.

Referring to FIGS. 6A-6C, in one embodiment, once the user is ready touse training device 10, the user will need to manipulate safety 44 toplace training device 10 into an armed position. In one embodiment, thearmed position (see FIGS. 7A-7C) is when the safety projections 44 a onsafety 44 no longer are in position to impede the movement of trigger 42proximally relative to housing 12. In one embodiment, the armed position(see FIGS. 7A-7C) is when needle guard 30 is moveable proximallyrelative to housing 12. In one embodiment, the armed position is whentrigger 42 is moveable by needle guard 30 rotative to latch 40. In anauto-injector, the armed position corresponds to when the user canactivate an injection. In one embodiment, removing safety 44 and safetycap 16 from housing 12, in either order, places training device 10 intothe armed position. In other embodiments, safety 44 and/or safety cap 16remain coupled to housing 12 in the armed position and movement ormanipulation (e.g., twist or slide) of safety 44 and/or safety cap 16relative to housing 12 causes training device 10 to enter into the armedposition.

In one embodiment, the user grasps housing 12 with one hand and pushesproximally on grips 44 e of safety 44 with the thumb of the same hand todecouple safety from housing 12. Safety 44 may be coupled to the housingby one or inure of tab 44 d, projections 44 a, arm 44 b or projection 44c. In one embodiment, the snap fit between projections 44 a and housing12 primarily couples safety 44 to housing 12. In one embodiment,removing projections 44 a from housing creates an audible click and/or atactile feel in the user's hand to indicate that safety 44 has beenremoved and training device 10 is in the armed position. Once Safety 14has been removed, in one embodiment, user grasps housing 12 with onehand and grasps safety cap 16 with their other hand and separates safetycap 16 relative to housing 12 to remove safety cap 16 from housing 12.In one embodiment, the user twists safety cap 16 relative to housing 12to remove safety cap 16 from housing 12. In one embodiment, removingsafety cap from housing 12 exposes a portion of needle guard 30extending from distal end 12 a of housing 12.

Referring to FIGS. 7A-7C, training device 10 is shown in the armedposition. In the armed position, needle guard 30 may extend from distalend 12 a a distance D₁. In one embodiment, distance D₁ simulates adistance Mat a needle guard would need to be retracted in anauto-injector to expose a needle during injection. Needle guard 30 maybe restricted from moving proximally relative to housing 12 byresistance tab 34 f extending through latch 40. In one embodiment, whena user grasps housing 12 and pushes the distal end of needle guard 30against an injection site, needle guard 30 moves proximally relative tohousing 12 until needle guard 30 abuts resistance tab 34 f. In oneembodiment, needle guard 30 moves a predetermined distance beforeabutting resistance tab 34 f. In other embodiments, needle guard 30initially abuts resistance tab 34 f in the armed position. In oneembodiment, once needle guard 30 abuts resistance tab 34 f apredetermined force is required for needle guard 30 to move relative tohousing 12. In one embodiment, continued force on needle guard 30relative to housing 12 caused by user holding housing 12 and pushing thedistal end of needle guard into their skin bends resistance tab 34 fand/or resistance arm 34 e until resistance arm 34 e deflects radiallyinwardly into latch 40 moving resistance tab 34 f out of the path ofneedle guard 30.

Requiring a predetermined force in an auto-injector to move a needleguard relative to housing from the armed position to a retracted orinjection position may help prevent accidental needle sticks. Accidentalbumps against the distal end of the needle guard do not exert enoughforce to retract the needle guard and expose the needle. Requiring apredetermined force may also help to ensure that the needle is, fullyinserted during use. A user will not be able to slowly insert the needleand prematurely withdraw once they feel the needle piercing their skindue to the speed of injection once the predetermined force is overcome.In other embodiments, resistance tab 34 f and the additionalpredetermined force is omitted such as by using lock 34′ as shown inFIG. 4. In one embodiment, only the resistance of biasing member 32resists movement of needle guard 30 relative to housing 12. In oneembodiment, continued force on needle guard 30 relative to housing 12caused by user holding housing 12 and pushing the distal end of needleguard 30 into their skin allows needle guard 30 to move a distance D₁.

Referring to FIGS. 8A-8C, training device 10 is shown as needle guard 30is being retracted into housing 12. In one embodiment, moving needleguard 30 proximally relative to housing 12 simulates a needle beinginserted in the user. As a needle guard in an auto injector isretracted, the needle extends distally from the needle guard penetratingthe skin of the user.

Referring to FIGS. 9A-9C, training device 10 is shown in the retractedor injection position. In one embodiment, fully retracting needle guard30 proximally relative to housing 12 simulates the injection step of anauto-injector. In one embodiment, needle guard 30 is substantiallyretracted into housing 12 in the retracted position. In one embodiment,as the proximal end of needle guard 30 moves toward and abuts trigger42, trigger 42 is slid proximally relative to latch 40. In oneembodiment, a distal edge of trigger is slid proximally past projection34 c of lock 34. In one embodiment, a distal edge of trigger is slidproximally past the apex of projection 34 c.

Referring to FIGS. 10A-10C, training device 10 is shown as biasingmember 32 moves needle guard 30 distally relative to housing 12 towardsthe second extended position. In one embodiment, needle guard 30automatically moves distally relative to housing 12 once the proximallyfacing force on needle guard 30 is less than the biasing force ofbiasing member 32 (e.g., as a user pulls housing 12 from their skin). Inone embodiment, the distal end of needle guard 30 remains in contact asthe user pulls housing 12 away from their skin. In one embodiment,movement of needle guard 30 distally relative to housing 12 toward thesecond extended position simulates removal of the auto-injector needlefrom the user. In one embodiment, movement of needle guard 30 distallyrelative to housing 12 toward the second extended position allowsprojection 34 c on lock 34 to extend radially from within latch 40.

Referring to FIGS. 11A-11C, training device 10 is shown a lockedposition. In one embodiment, needle guard 30 is not retractable relativeto housing 12 in the locked position. In one embodiment, locking needleguard 30 relative to housing 12 in the locked position simulates theauto-injector after use where the needle guard covers the needle tip andprevents reuse. In one embodiment, needle guard 30 extends from distalend 12 a of housing 12 a distance D₂. In one embodiment, distance D₂ isequal to distance D₁ (see FIG. 7B). In other embodiments, distance D₂may be greater or less than distance D₁. In one embodiment, once needleguard 30 extends distally longitudinally past lock tab 34 b, lock arm 34a is radially biased by the spring force of lock arm 34 a towards itsnatural shape such that lock tab 34 b extends through latch 40 and intothe sliding path of needle guard 30. In one embodiment lock tab 34 bprevents needle guard 30 from retracting or moving proximally relativeto housing 12 toward the retracted position.

Referring to FIGS. 12A-12C, training device 10 is shown in a resetstorage position. Safety 44 may be actuated to return training device 10to the initial or storage position for subsequent training. Thoughcertain auto-injectors may not be reusable, training device 10 may beresettable and used multiple times. In one embodiment, safety 44 isrecoupled to housing 12 to move training device 10 from the lockedposition to the storage position. In one embodiment, projections 44 aextend through housing, abut trigger 42 and slide trigger 42 over latch40. In one embodiment, as trigger 42 slides relative to latch 40,projection 34 c of lock 34 extends through notch 42 c (see FIG. 2) oftrigger 42. In one embodiment, as trigger 42 slides further relative tolately 40, flattened portion 42 a of trigger 42 slides over projection34 c to radially bias lock arm 34 a inwardly into latch 40 and move locktab 34 b into latch 40 and out of the path of needle guard 30 to resettraining device 10. In one embodiment, trigger 42 alone moves lock tab34 b into latch 40. In other embodiments, projection 44 c of safety 44assists in moving lock tab 34 b into latch 40. In one embodiment, aftersafety 44 is coupled to housing 12 and training device 10 is reset tothe storage position, safety cap 16 may be recoupled to distal end 42 aof housing 12 (see FIGS. 5A-5C). In other embodiments, training device10 is used again without recoupling safety cap 16.

It will be appreciated by those skilled in the art that changes could bemade to the exemplary embodiments shown and described above withoutdeparting from the broad inventive concepts thereof. It is understood,therefore, that this invention is not limited to the exemplaryembodiments shown and described, but it is intended to covermodifications within the spirit and scope of the present invention asdefined by the claims. For example, specific features of the exemplaryembodiments may or may not be pan of the claimed invention and variousfeatures of the disclosed embodiments may be combined. Unlessspecifically set forth herein, the terms “a”, “an” and “the” are notlimited to one element but instead should be read as meaning “at leastone”.

To the extent that the method does not rely on the particular order ofsteps set forth herein, the particular order of the steps should not beconstrued as limitation on the claims. The claims directed to the methodof the present invention should not be limited to the performance oftheir steps in the order written, and one skilled in the art can readilyappreciate that the steps may be varied and still remain within thespirit and scope of the present invention.

We claim:
 1. A training device for training a user on the operation ofan auto-injector that dispenses a medicament, the training devicecomprising: a housing having a distal end and a proximal end; a needleguard slidable relative to the housing from a first extended positionprior to operation of the training device, to a retracted positionduring operation of the training device, and to a second extendedposition after operation of the training device; a lock configured tolock the needle guard in the second extended position; a safety coupledto a proximal portion of the housing, the safety preventing movement ofthe needle guard from the first extended position to the retractedposition with the safety in a storage configuration, the needle guardmoveable into the retracted position with the safety in an armedconfiguration; and a cap coupled to a distal portion of the housing, thecap configured to prevent movement of the needle guard when the cap iscoupled to the distal portion of the housing.
 2. The training device ofclaim 1, wherein the lock is a leaf spring.
 3. The training device ofclaim 2, wherein the leaf spring includes a first leg and a second leg.4. The training device of claim 3, wherein the first leg includes aradially extending lock tab that restricts movement of the needle guardrelative to the housing in the second extended position, and the secondleg includes a radially extending resistance tab that provides aresistance force that must be overcome to move the needle guard to theretracted position.
 5. The training device of claim 4, wherein the firstleg includes a projection proximal to the lock tab.
 6. The trainingdevice of claim 3, wherein the first leg includes a radially extendinglock tab that restricts movement of the needle guard relative to thehousing in the second extended position.
 7. The training device of claim2, wherein the leaf spring includes a single leg.
 8. The training deviceof claim 2, wherein the leaf spring is attached to the actuationassembly by a fastening means.
 9. The training device of claim 8,wherein the fastening means is a rivet.
 10. The training device of claim1, further comprising: an actuation assembly coupled to the needle guardand controlling the movement of the needle guard from the retractedposition to the second extended position, wherein the actuation assemblyincludes a biasing member and a trigger, the trigger retaining the lockin the storage position, the needle guard sliding the trigger off of thelock when the needle guard is moved from the first extended position tothe retracted position.
 11. The training device of claim 10, wherein thesafety slides the trigger back over the lock as the safety moves to thestorage configuration.
 12. The training device of claim 1, wherein thesafety is removably coupled to the housing and removing the safety fromthe housing allows the user to urge the needle guard into the retractedposition when the safety is the in the armed configuration, andreattaching the safety to the housing resets the lock to an unlockedconfiguration.
 13. The training device of claim 1, wherein the needleguard extends from the distal end of the housing in the first extendedposition a distance equal to a distance the needle guard extends fromthe distal end of the housing in the second extended position.
 14. Thetraining device of claim 4, wherein a predetermined force, in additionto the resistance force of the radially extending resistance tab, mustbe exerted on the needle guard relative to the housing to move theneedle guard out of the first extended position.
 15. The training deviceof claim 1, wherein a first projection of the safety extends into theproximal end of the housing and a second projection of the safetyextends into a sidewall of the housing in the storage position.
 16. Thetraining device of claim 1, wherein the training device does not includea needle.
 17. The training device of claim 1, wherein the trainingdevice does not contain medicament.
 18. The training device of claim 1,wherein the training device is not capable of injecting medicament. 19.The training device of claim 1, wherein the cap includes a projectionconfigured to engage a corresponding projection on the needle guard. 20.The training device of claim 1, wherein the cap is detachably coupled tothe housing.
 21. The training device of claim 1, wherein the cap isdetachable from the housing and reattachable to the housing withoutimpacting the storage position of safety or needle guard.